This invention relates to a stirrer of a machine for making and dispensing ice cream products.
More specifically, reference is made in this description to machines for making and dispensing soft ice cream.
Machines of this kind usually comprise a mixing and freezing cylinder inside which a basic product is mixed and cooled to obtain a finished product.
Inside the cylinder, the machine is equipped with a power-driven stirrer which not only mixes the basic product continuously to make the finished ice cream as smooth as possible but, at the same time, also causes the finished ice cream to advance towards a dispensing nozzle.
One problem suffered by these machines regards the formation of a layer of ice or frozen basic product on the inside wall of the mixing and freezing cylinder.
Indeed, while the product is being stirred, pieces of this ice layer come away from the cylinder wall and fall into the product being made.
This not only worsens the quality of the finished ice cream, which is less smooth on account of the pieces of ice of various sizes inside it but also creates the risk of damaging the stirrer because the pieces of ice impact the stirrer as it rotates.
For this reason, prior art stirrers are equipped with elements, called “scrapers”, which prevent the formation of the layer of ice by continuously scraping the inside wall of the mixing and freezing cylinder while the stirrer rotates.
Normally, however, during use of the machine, the stirrer is never fully immersed in the product or in the ice cream being processed which means that in very long operating cycles, a certain amount of basic product, ice cream, or ice tends to stick and build up on the stirrer.
These build-ups remain on the stirrer and are not mixed into the rest of the product being processed which means that over time, they harbor bacteria, which reduces the quality of the ice cream produced and makes it unsafe for consumption.
It is therefore necessary to subject the stirrers and, in particular, the scrapers, to periodic cleaning cycles.
Some prior art types of stirrers consist of a single metallic “body” and the scrapers form an integral part of the stirrer structure. These stirrers have a very complex structure and reaching all parts of it is very difficult Correct and thorough cleaning of all its parts is not therefore guaranteed.
In other types of stirrers known in the prior art, the scraper is a separate part which is mounted to the stirrer using springs and other elastic elements.
These systems, however, are somewhat awkward to dismantle and their maintenance is a lengthy, painstaking task.
Moreover, owing to the complexity of these systems, correct cleaning of all the parts is, again, not guaranteed and there is the risk of bacteriological contamination in this case, too.